Fix a few more list markup issues.

Fix a few more list markup issues.

* lisp/muse-publish.el (muse-publish-surround-dl): Begin this function
  for definition list markup, but it's not useful yet.
  (muse-publish-surround-text): Accept post-indent argument, and use it
  to strip extra space from indented lists, hopefully in a smart way.
  (muse-forward-list-item): Don't explicitly move the point unless
  another list item of the same type is encountered.
  (muse-publish-markup-list): Calculate post-indent correctly, and make
  use of it.
git-archimport-id: mwolson@gnu.org--2005/muse--main--1.0--patch-334